There has been extensive prior use of the general concept of embedding various types of information in video, audio, sound, text, and other multimedia formats. There are two main approaches that have heretofore been employed to achieve these ends: 1) extending the format or creating a new format which contains that type of data; or 2) embedding the data, using techniques which allow the data to be recovered, but which do not affect the backwards compatibility of the format.
Examples of the second type of approach arise frequently in communication and entertainment media; for example, the backwards compatibility of color-television broadcast, or the transmission of subtitles and other information embedded in a video signal. Another example of a very popular application is the encoding of identification information in a media file so that it is robust to degradation, and transformation of the media file generally for purposes such as intellectual-property protection—often referred to as “watermarking”. These techniques and others of similar character are directed, however, towards the embedding of relatively low bit-rate data, roughly on the order of 22 binary digits (bits) of data per second. Such data typically consists of short and simple ASCII text or other unique identifiers. In another application, a control code is used for a computer system, to provide a very short signal control code as for preventing the computer from copying a copy-protected data file.
Among prior patents illustrative of such and related techniques and uses are U.S. Pat. No. 4,379,947 (dealing with the transmitting of data simultaneously with audio); U.S. Pat. No. 5,185,800 (using bit allocation for transformed digital audio broadcasting signals with adaptive quantization based on psychoauditive criteria); U.S. Pat. No. 5,687,236 (steganographic techniques); U.S. Pat. No. 5,710,834 (code signals conveyed through graphic images); U.S. Pat. No. 5,832,119 (controlling systems by control signals embedded in empirical data); U.S. Pat. No. 5,850,481 (embedded documents, but not for arbitrary data or computer code); U.S. Pat. No. 5,889,868 (digital watermarks in digital data); and U.S. Pat. No. 5,893,067 (echo data hiding in audio signals),
Prior publications describing such techniques include [0006] Bender, W. D. Gruhl, M Morimoto and A. Lu, “Techniques for data hiding”, IBM Systems Journal, Vol. 35, Nos. 3 & 4, 1996, p. 313-336; [0007] MPEG Spec—ISO/IEC 11172, parts 1-3, Information Technology—Coding of moving pictures and associated audio for digital storage media at up to about 1.5 Mbit's, Copyright 1993, ISO/IEC; and [0008] ID3v2 spec:
A survey of techniques for multimedia data labeling and particularly for copyright labeling using watermarking through encoding low bit-rate information is presented by Langelaar, G. C. et al in “Copy Protection for Multimedia Data based on Labeling Techniques